toddfarmer
commented
8 years ago Note: Comment by Wes McKinney (wesm): Resolved in https://github.com/apache/arrow/commit/c06b7654bccfe8c461869a6e5922668896c27c45
Closed toddfarmer closed 8 years ago
toddfarmer
commented
8 years ago Note: Comment by Wes McKinney (wesm): Resolved in https://github.com/apache/arrow/commit/c06b7654bccfe8c461869a6e5922668896c27c45
Note: This issue was originally created as ARROW-56. Please see the migration documentation for further details.
Original Issue Description:
In https://github.com/apache/arrow/blob/master/format/Layout.md, we describe bitmaps for nulls (presumably same encoding for boolean data) and provide the C code for accessing a bit:
bitmask[j / 8] & (1 << (j % 8))Implicitly this is LSB bit-endianness (https://en.wikipedia.org/wiki/Bit_numbering) – see the discussion of bitpacking in the Parquet format: https://github.com/apache/parquet-format/blob/master/Encodings.md#run-length-encoding--bit-packing-hybrid-rle--3
If this is what we want, we should make this aspect of the format explicit.
Migrated issue participants:
Reporter: Wes McKinney (wesm) Assignee: Wes McKinney (wesm)